1. Field of Invention
The invention relates to an image processing method and, in particular, to a method that calibrates the image dispersion phenomenon when capturing an image to achieve image chromatism compensation.
2. Related Art
Image capturing devices often face the image dispersion problem. The reason such a problem occurs is because the RGB channels in the image have distinct wavelengths and diffraction indices. Therefore, after the light passes through the lens of the image capturing device and is processed by the photo sensor, one always encounters the image dispersion problem. When the problem becomes serious, the output image will not look right. Therefore, we have to make image chromatism compensation.
In order to completely solve the image chromatism issue, one has to return to the problem of image dispersions. A well-known method is to make precision designs on the hardware part of the image capturing device. Usually, one modifies the focusing power of lenses so that the three colors can be converged together and received by the photo sensors. Indeed, this can solve the image chromatism problem. However, this method has at least the following two drawbacks. (1) the hardware design precision is limited. It is because the current technology cannot catch up with the precision requirement. Even if one uses the most precise manufacturing technology to fabricate the lenses, the image dispersion problem still cannot be satisfactorily solved. (2) The hardware design has a higher cost. Therefore, it is useless to spend a lot of money to design a lens that cannot achieve the required precision and still have the image dispersion problem. This is a big reason why such a method cannot be widely accepted.
How to use a computer program to help completely solving the image dispersion problem at a cheaper cost should be an interesting alternative for people in the field.